One time I didn't stir my pea soup frequently enough and it stuck to the bottom. Without stirring up the burnt parts, I dumped it all into a second pot (stainless steel). All the burnt stuff was still in the other pan which I cleaned and went back to my other pot.

I put a cast iron frying pan on the stove (it would distribute heat much better then a pot). I put the stainless steel pot inside the cast iron frying pan and put vegetable oil around the inside of the cast iron frying pan. This would absorb the heat from the frying pan and distribute it evenly around the pot. I kept the oil in the frying pan hot enough to simmer the pea soup.

Well what do you know? It worked - no more stuck soup! I stirred the pea soup about every 10 or 15 minutes just to keep it mixed up.